Conventionally, known as a card reader for reading magnetic data recorded in the card is a manual card reader with which a user manually handles the card (For example, refer to Patent Document 1). A card reader described in Patent Document 1 is a so-called swipe-type card reader with which reproduction and so on are carried out with respect to magnetic data of a card, while the card being transferred along a groove card path that is so shaped as to be shallower than a width-wise dimension of the card.
In the card reader described in Patent Document 1, one end and the other end of the card path function as a first card door way and a second card door way, respectively. In the card reader, a first sensor and a second sensor, both for detecting a card being inserted, are placed in the proximity of the first door way as well as in the proximity of the second door way, respectively. Furthermore, in the card reader, a first magnetic head and a second magnetic head are placed so as to face each other across the card path. In the card reader, the first magnetic head turns on so as to become ready for reproduction and so on with respect to magnetic data by the first magnetic head when the first sensor detects a card being inserted. In the meantime, the second magnetic head turns on so as to become ready for reproduction and so on with respect to magnetic data by the second magnetic head when the second sensor detects a card being inserted.
Moreover, as a conventional manual card reader, also known is a so-called dip-type card reader with which reproduction and so on are carried out with respect to magnetic data at the time when a card is inserted into, or pulled out from the card reader (For example, refer to Patent Document 2). The card reader described in Patent Document 2 is equipped with two sensors, as those for detection of a card inserted, while one sensor is placed at an inlet port side in a card traveling path, and the other sensor is placed at a rear side of the card traveling path.    Patent Document 1: Japanese Unexamined Patent Application Publication No. SH062-102492    Patent Document 2: Japanese Unexamined Patent Application Publication No. 2003-271909
In the card reader described in Patent Document 1, reproduction and so on with respect to magnetic data by the first magnetic head become enabled when the first sensor detects a card being inserted, and meanwhile reproduction and so on with respect to magnetic data by the second magnetic head become enabled when the second sensor detects a card being inserted. Accordingly; if an error, such as a breakdown and the like, happens to either the first sensor or the second sensor, reproduction and so on with respect to magnetic data by the first magnetic head or the second magnetic head, respectively, cannot be carried out. Therefore, in case such an error happens to either the first sensor or the second sensor, immediate replacement of the first sensor or the second sensor, respectively, is needed. In the meantime, unfortunately the card reader has no function for detecting a fact that such an error has happened to the first sensor or the second sensor.